The present invention relates to a windowpane antenna apparatus attached to a windowpane of a vehicle such as an automobile.
Conventionally there is an automobile windowpane antenna apparatus as the most typical one for use in vehicles. In the automobile windowpane antenna apparatus, a thin, narrow conductive strip is provided on an automobile windowpane (usually a rear window glass) and employed as an antenna.
Recently a defogger serving as a heater for clearing condensed moisture, has been provided on almost all over a rear window of an automobile. Therefore, a space for providing the above conductive strip as an antenna is limited to a small one interposed between the defogger and the frame of the window.
The conventional automobile windowpane antenna apparatus has the following problem. The space in the windowpane on which an antenna can be mounted, is very small.
However, there has recently been a demand for receiving TV broadcasting waves and GPS waves and transmitting/receiving portable telephone waves as well as FM/AM broadcasting waves, and there has been a strong request to satisfy the demand only by a windowpane antenna apparatus.
However, it is physically impossible to provide different antennas separately in the above small space of a windowpane. If they were done, an interference would occur among the antennas thereby to degrade the characteristics thereof.